Epoxy EPS Construction Tips
Epoxy EPS Construction Tips
(Compiled by Rob Olliges, October 2004)
Contact Greg Loehr, email: or 321-223-5276 (cell phone)
Resin Research
131 Tomahawk Dr.
Indian Harbour Beach, Fl. 32937
Ph. 321-779-2369
Resin Research
4231 S. Fremont Av.
Tucson, Az. 85714-1628
Ph. 321-223-5276
Greg Loehr -- We ship UPS everyday. COD is our preferred method, so no problem there. You can call Sam @321-779-2369 or you can call me @ 321-223-5276 to place orders or through e-mail @ .
Different Resins & Hardeners:
Mixing hardeners for custom applications is one of the reasons we made everything 2 to 1.
With fast, you have a 25 min pot life, slow 50 min and extra slow 200 min. Slow has 4-6 hours flip time; fast has 2-3 hours flip time.
Mixing different hardeners together will give you other results and there isn't any algebra necessary.
In most conditions you'll find our standard 2000 resin on PU to have similar flex characteristics to polyester although your weights will be lighter with the same glass schedule. EPS blanks with heavier glass schedules with 2000 will be a bit stiffer. We also have 2020 resin which is more flexible and 2040 (in development) which will have even more.
Price List:
Prices are FOB Tucson Az. or Melbourne Fl.
3 Pt set: 2 Pt. Resin, 1 Pt. Hardener: $26
1.5 Gal. set: 1 Gal Resin, 1/2 Gal. Hardener $85
3 Gal set: 2 Gal Resin, 1 gal. Hardener $155
7.5 Gal. set: 5 Gal Resin, 2.5 Gal. Hardener $348
15 Gal. set: 10 Gal. Resin 5 Gal. Hardener $626
Advantages of Resin Research Epoxy:
Greg Loehr -- Monday, 10 November 2003, at 9:05 a.m.
Here are some of the advantages.
Epoxy is stronger so the board comes out stronger with better resin
Since epoxy is stronger it takes less resin in the laminate to do the same job as polyester. And epoxy has a slightly light specific weight. This makes a lighter board even with the same blank used for the poly. In fact with epoxy on Clark foam you can use a green blank and it will come out the same weight as the same glassed poly lamination using a blue. And MUCH stronger.
You can laminate ANY foam with epoxy. Not just urethane. This gives you the option of making your own blanks.
Our new epoxy system as fast as MEK initiated poly so production times are quicker than in the past.
Cosmetically epoxy is clearer making a whiter board. Yellowing is also slower than with poly.
Epoxy can be cleaned up with soap (GoJo type) and water. There is no need for clean up solvents.
Our Epoxy has very little vapor (odor) so work can be done almost anywhere. No masks are necessary with just moderate ventilation.
You use approximately 1/3 the amount of epoxy resin to build a board as you would polyester.
These last three, immediately above, give you an indication of the reasons epoxies are better for the environment and for labor.
Epoxy gives the laminator more work time and there is no real "gel" time to catch you. The resin just gradually thickens as it begins to harden. This allows a higher quality laminate.
All the newer fabrics (Kevlar, carbon, s glass, etc.) were designed for use with epoxy. Not surprisingly, they all perform best in an epoxy matrix.
On the health issues, with our epoxy (Resin Research), I have never seen any sensitization that doesn't involve a co-toxin. The one in particular in our business is acetone. It serves as a vehicle for toxins through the skin. We eliminated acetone from our shop long ago and have never had any problems. We now use soap and water, which work better anyway. Our resins also do not contain phenol or formaldahyde, which many other systems do. These are some other co-toxins I mentioned above. Also our hardeners are based solely on cycloaliphatic diamine technology as opposed to straight chain amines. This also reduces toxicity. We also have safeguards built into our formulations to reduce toxicity. This makes our hardeners much safer to use than most other epoxies.
Epoxy Safety Issues
Toxicity. Vapor from most epoxies is much lower than it's polyester counterparts. The resins we produce (Resin Research Epoxies) are all high solids and have 1/50th the vapor of polyester surfboard resins. In our shop (which is well ventilated) we don't even wear masks. Epoxy is also NOT a carcinogen. That has been well proven by OSHA and many others in industry. What epoxy is, is a skin sensitizer. This varies greatly between different epoxy systems depending on different company’s formulations. Most older epoxy hardeners are formulated with a chemical known as TETA or another called DETA. These base hardeners are in the aliphatic amine family, are very reactive, somewhat unstable, quite toxic and easily can cause sensitization of the skin (or dermatitis). Most of these hardeners are also modified with phenol and formaldehyde. Phenol is what dermatologist use for chemical skin peels and increases TETA and DETA's toxicity to the skin dramatically. Many of these older hardeners are up to 50% phenol. Formaldehyde is also no picnic as it also increases risk because of it's ability to act as a vehicle for the phenol and amines through the skin and into the blood system. By the way, the reason these epoxy hardeners are still used today is because they're CHEAP. DETA and TETA cost 1/5 what a modern diamine based hardener costs to produce. Anyone who has worked with many of the West System epoxies are familiar with these low cost systems. Modern epoxy hardeners are nothing like their 60's counterparts. As I mentioned above, they are formulated with modern diamines and have vastly reduced incidences of sensitization. They also have lower vapor, better color, better finish, and lower exotherm. They contain NO phenol and NO formaldehyde. Our company was one of the first in the US to formulate and market diamine based epoxy hardeners 20 years ago, which gives us an edge in experience with these chemicals. As superior as they are they still must be respected as skin sensitizers. The simple way to eliminate problems related to dermatitis in the workplace is to reduce or preferably eliminate contact with the skin. This means gloves. That's it. We wear disposable vinyl gloves. Vinyl is preferable to rubber because rubber gloves are also skin sensitizers. The other, even more harmful, ingredient is contaminated acetone. Like formaldehyde above it is a vehicle for toxins into the bloodstream. Fortunately epoxy can be cleaned up with soap and water. Not standard bar soap but with products like Go-Jo and Fast Orange. These products are water based and don't act as a vehicle the way VOC solvents do. In 20 years of producing epoxy surfboards we have NEVER had one incidence of dermatitis in our shop. I have also NEVER seen a case of dermatitis that didn't have something to do with the co-toxin acetone. Given the aforementioned resin parameters and if shop practice adheres to the above suggestions, epoxy resins are MUCH safer to use for producing surfboards than their polyester counterparts.
Greg Loehr 5 March 2003
Additive F:
Greg Loehr -- Wednesday, 19 February 2003, at 7:35 p.m.
First, as I've stated earlier Additive F is a miracle breakthrough in the production of epoxy surfboards. It does so many things it's unbelievable.
In laminating, it helps wet the cloth eliminates most air bubbles, especially around wings and boxes, reduces the amount of resin needed, and most of all eliminates blush. Blush is what causes the banana peel effect you were referring to. In hot coats it eliminates blush, fish eyes, other surface blemishes and increases Barcol hardness. This increase in Barcol makes the board sand easy and improves the bond and strength between layers.
It also doesn't interfere with recoating as wax solution in polyester does. That means no sanding between layers. One of the things I've tried to relay on this site is that epoxy boards have become easier to make (and safer as well) than polyester boards. Somehow I don't think that has gotten through.
Additive F reduces resin use by about 20% in laminates.
How much?:
1cc per ounce of hardener = Laminations
2cc per ounce or hardener = Hot/Gloss Coats
EPS vs. XPS:
XPS (extruded polystyrene) generally does not wick water. That's not the problem with it. The building material industry got nailed for using EPS (expanded polystyrene) because it DID wick water. It (EPS) is now available with new technology that doesn't (EDRO technology) He was right that XPS does delaminate because of trapped blowing agent gasses and this is XPS' great failing in surfboard construction. Meanwhile the advances in EPS have answered the issues involved with it and it now presents a very fine material for both surfboard and house construction. EPS boards never bubbled. But XPS does, big time. Always has.
Greg Loehr -- Wednesday, 19 February 2003, at 8:06 p.m. Polystyrene (EPS) is my personal first choice. About two years ago a new technology sprung up from Europe called EDRO. EDRO machines are a new computerized version of the old EPS (expanded polystyrene) press technology. It makes an EPS foam with significantly enhanced strength and fusion that doesn't leak when dinged. The first EDRO machines installed in the US were done here in Florida. They are now across the US with two in Fl. and at least two in California. This technology takes polystyrenes strength to weight advantage and combines it with a foam that doesn't leak or delaminate.
Another question in this tread was about Shulers foam being used by Patagonia and others. This is an extruded polystyrene (XPS). I was the Dow distributor for a similar product about 12 years ago. The problem we had then, and the problem that continues to plague it today, is delamination. This is caused by the fact that a significant amount of blowing agent is trapped in the cells during production. Blowing agent expands under heat. That's what makes it work. 95% of the blowing agent in EPS foam is lost during the pre-expansion process. 95% of what's left is lost in the molding or press cycle. With urethane the chemicals are being changed during the polymerization process and you end up with only CO2 left in the cells. But with XPS the cells are left filled with blowing agent gases. When these cells are damaged, and the gas released is then heated, a delamination or bubble forms under the glass. Also these foams are copolymerized with polyethylene which NOTHING sticks to. This makes the problem even worse. This problem has existed with XPS since Bob Simmons first used it in the 50's. Also the new Solomon blank is based on an XPS foam so don't go holding your breath on that one either. While it's true that these foams are superior as far as being water tight, today I'll go with EDRO EPS
Greg Loehr 1 Sept 2004
I prefer EPS over XPS. XPS has a lower melting point and is basically unstable at 165¼f. EPS becomes unstable at 185¼f and that 20 degrees makes a big difference. On the other hand XPS is watertight and doesn't suffer from water intrusion the way EPS and urethane do although this issue is no longer a large one on either of these. All foams today have issues because of the low densities we use. In my experience EPS has the best balance of features.
Epoxy Laminating
Greg Loehr -- Wednesday, 26 February 2003, at 8:21 p.m. I wrote this to one of the major California glass shops that are now investigating alternatives. I thought it had some good info to post here on Swaylocks.
Below I'm writing some tips on making our stuff easier to use. If you take your time epoxy is actually easier to laminate than polyester, uses much less material and eliminates harmful chemicals in the factory.
1. Mix ratio must be adhered to. Deviation from the mix ratio will keep the resin from attaining a full cure. Also the material must be THOROUGHLY mixed. If not there can be soft spots. We use metered buckets (I'm sending you one which we get at the local hardware store) to assure proper mix. We use large paint stir sticks (like the ones hardware stores give you to stir paint). All our resins are 2 to 1 mix ratio by volume. The metered buckets work unreal, actually better than pumps and we laminate right out of those buckets.
2. Additive F. We use it in every batch we shoot, including laminates. It eliminates blush which is the biggest problem in building epoxy boards. It only takes 1cc per ounce of hardener in the mix. We put it in after pouring the resin and hardener into the bucket and then mix them all at once. It makes the resin a bit cloudy but clears out when the resin cures.
3. When laminating, the first thing to do is to pour all the resin out and spread it over the glass. You then wet the rails and tuck them. This gives the resin time to soak into the cloth on the flats. Polyester must be pushed through the cloth. Epoxy just soaks in and it does that in its own good time. It can't and shouldn't be forced. Additive F actually helps with this quite a bit. After it soaks in, squeegee out any air and remove any excess. We use plastic, "spreader," type squeegees. We've found that they move epoxy better than rubber squeegees do. They take a couple boards to get wired but after the initial learning curve laminating is much easier.
4. We use VERY little resin. Below is an example of our use levels for different size boards. As there is no "gel" time, any resin left over can be used on the next board. If you run short you can easily mix up additional resin to finish with. Usually we just work out of one bucket and simply keep mixing more material as needed. It isn't the same, "this bucket for this board," as polyester. These are estimates for total mixed material.
6' and under - 9 -12 oz. bottom 12-15oz. deck
7' and under - 12 -15oz bottom 15-18 oz. deck
(Epoxy beginners should add a couple ounces to these numbers).
8' and under - 18 - 21 oz bottom 21- 24 oz. deck
9' and under - 24 - 27 oz bottom 27- 33 oz deck
Hot coats run just a bit more than an ounce per foot. For instance a 6' board would take about 7 oz. per side. Longboards, 9', take about 12-15 oz. per side. If you’re glossing use a bit less than a hot coat. We use 3" disposable white bristle brushes for hot coating. We don't clean them. We use them for one batch and pitch em. Not only do we feel that their not worth cleaning but we've also had problems in the past with contamination from cleaned brushes which manifested itself in bad hot coats. New brushes always make for clean hot coats.
5. Do not use acetone for clean up and never let contaminated acetone touch the skin. Any toxicity problems we've seen in the past always included contaminated acetone. Not only that but acetone doesn't work that well with epoxy anyway. Leaves everything sticky. For your hands use disposable vinyl gloves. Clean gloves between boards with scrap fiberglass. I usually cut scrap and pile it neatly on the table so I have plenty ready. Clean your squeegee with scrap glass. Anytime the squeegee gets slick I just wipe it and my gloves down. When the gloves get funky, peel em off and put on a new pair. 10 cents a pair is cheaper than acetone. With so little resin being used very little goes anywhere except on the board so things tend to stay much cleaner. We don't ever get more than a drop or two on us. If you do get some on you, use Go-Jo or Fast Orange or some other waterless cleaner with water to get it off. These clean epoxy more effectively and are much safer to use than acetone.
I think that's it. You shouldn't have any problems but if you do my phone number is on the bottle. I also have a cell # 321-223-5276 which I usually have with me always. Thanks for the order and good luck. Sincerely, Greg Loehr
Lam Tips:
Greg Loehr -- Friday, 4 April 2003, at 9:40 p.m. Guys, I read below the issues your having with epoxy wet out. The problem is that you’re still thinking polyester technique. Epoxy doesn't need to be pushed into the fabric. If you do this it will get frothy. [GO SLOW].
The first thing to do after mixing is to pour all the resin on the board and spread it around so the entire surface is covered. Then wet your laps by pulling resin off the flats onto the lap. This gives the resin time to soak into the flats. Also, use a stiff squeegee that moves the resin more effectively. I use one of those plastic spreaders, the yellow ones. After you wet and tuck the laps, the resin should have sufficiently soaked into the flats with no elbow grease. Now simply remove the excess while flattening the fabric and clean your laps. It's that simple. Also by pouring all the resin out immediately you reduce exotherm and lengthen work time. Using the above technique I laminated a 12 foot board with a 3 layer 6 oz deck the other day with our new fast hardener in 85º with time to spare.